Tag: mineral resources - coal - introduction

Lignite is a lower grade coal and contains about 40 to 55% carbon. It has low heating power and emits smoke. Its colour varies from dark to black brown.  

The yellow colour flame is seen when bituminous coal is burnt due to incandescence of very fine soot particles that are produced in the flame. This type of flame only burns at around 1,000 °C. Depending on the lighting, you may have actually seen the soot rising from the flame.

Anthracite is the best quality coal. It burns slowly and generates great heat, with very little smoke. Its carbon content is 80 to 95%. Only 5% of the world's coal is of this type.

Bituminous coal contains moisture up to approximately 17 percent. About 0.5 to 2 percent of the weight of bituminous coal is nitrogen. Its fixed carbon content ranges up to approximately 85 percent, with ash content up to 12 percent by weight.

When the Lignite is burnt the flame is in brownish color. Lignite is a low grade brown coal, which is soft with high moisture content.

Caol is known as "Black Diamond". This is a fossil fuel which was formed millions of years ago when giant fern and swamps got buried under the layers of the earth. Coal is therefore referred to as "Buried sunshine". Electricity from coal is called "Thermal Power".

Anthracite also is the most brittle among coal types. When burned, it produces a very hot, blue flame.